Various schemes have been devised for analyzing human breath samples to obtain information about a person, particularly information relating to the person's percent blood alcohol concentration (BAC). However, shortcomings and deficiencies still exist in the technology.
Specifically, existing breath analysis techniques simply do not provide approaches for gathering information other than BAC about the person from a breath sample. Examples of existing technology are discussed below.
U.S. Pat. No. 4,093,945 to Collier et al discloses a breath testing system for alcohol intoxication breath testing. The system includes (1) a breath input unit, (2) a controller which delivers a sample of deep lung breath to (3) an evaluator including an alcohol detector and an output apparatus. The controller includes a breath flow sensing means to insure that a deep lung breath sample is tested. A passing signal cannot be obtained unless (a) the predetermined continuous and uninterrupted flow has occurred, and (b) the resulting sample tests below a predetermined alcohol concentration.
U.S. Pat. No. 4,316,380 to Heim et al shows means for determining the breath alcohol content of a test person. The system (1) measures the alcohol content of the breath to produce an alcohol content signal, (2) measures the change in the alcohol content signal, (3) measures a flow of the breath of the test person, and (4) indicates the alcohol content using the alcohol content signal only when the change in the signal per unit time is below a pre-selected change value and the flow is above a pre-selected flow value, and further where the flow has not dropped below the predetermined flow value since it first reached the predetermined flow value.
U.S. Pat. No. 4,317,453 to Heim et al discloses a system for testing a person's breath for the determination of its alcohol content. The system first determines when the breathing air is at a condition in which breath testing results will be effected. This is done by arranging a capacitor in a breathing tube through which the breathing air is detected.
First, the capacitor is heated to a predetermined temperature. Then the breathing air is directed over it so as to cool the capacitor until it has attained a predetermined temperature change. This temperature change is such that it will take place when the person's breathing air has its desired consistency.
When this occurs, the breathing air is then directed into a test chamber, in which it is tested to determine the constituency of the breathing air, particularly the percentage of alcohol which it contains. The device for testing the person's breath also contains a test chamber connected to the tube with a control means. This control means senses the temperature of the capacitor and then permits the flow of the gas into the test chamber only after a predetermined temperature drop has occurred.
U.S. Patent Application with Ser. No. 06/494,301, filed May 13, 1983 by Brian P. Elfman and Lawrence T. Rojahn, now abandoned, discloses an apparatus for measuring the blood alcohol concentration (BAC) of an individual. The apparatus includes (1) a gas vapor sensor for receiving and analyzing the alcohol concentration in the breath of the individual, (2) an analog-to-digital converter, and (3) a gas analyzer for detecting the rate of change of the signal generated by the sensor.
When the rate of change of the signal is at or near zero, thereby indicating the breath is deep lung air, the sensor signal is transported to a BAC reading in the BAC look-up table. The BAC reading is then compared to a pre-recorded level obtained from a memory, to determine the intoxication level of the individual. A flow sensor can be provided to assure that the individual is expelling a sufficient volume of air to assure a good reading. An auto ignition gate can be provdied to disable a vehicle if the individual is found to have a BAC reading above a predetermined level which indicates intoxication.
While the above technology does offer laudible approached and solutions with respect to the particular situation each addresses, none of them individually or in combination disclose or suggest the Invention defined in the appended claims of this present case. Specifically, the following problems persist despite the efforts of the existing technology.
All the above approaces are specifically directed to determining the BAC of a person in order to prevent that person from operating a vehicle if he is inebriated. No additional information can be determined by these systems from the breath sample. These samples are not sophisticated enough to accurately and reliably screen users to ensure that only an authorized person is tested.
Existing breath analyzing equipment, to provide a breath sample test result which can be introduced into evidence in a drunk driving prosecution, (a) must be built to very precise specifications, (b) are large and not easily transportable, and (c) are sensitive and thus require frequent servicing in order to remain precisely calibrated. As a result, the available equipment is quite expensive.
Because the accurate equipment is not easily transportable, an arresting police officer faces a race against time in getting an inebriated person to the equipment's location quickly enough that a person's body does not metabolize the alcohol prior to a BAC test.
Additionally, these systems have difficulty in accurately detecting attempts to deliver bogus breath samples to them, for example in the case where inebricated person #1 has a breath sample delivered by a sober person #2. The opportunity also exists to introduce a bogus breath sample originating in a compressed air bottle or having been filtered prior to being subjected to a BAC test.
These are only a few of the problems which have not been adequately resolved by the existing technology. Because of these problems, it became necessary to devise the Invention (1) disclosed by example below, and (2) defined in the appended claims.